Is Islamic midnight the same as 12:00 am?

No, and it usually is not close. Islamic midnight is the midpoint between Maghrib and the next day's Fajr. In London in June that falls around 12:40 am; in December, closer to 11:50 pm. Clock midnight is a civil convention tied to timezones and daylight saving, neither of which has anything to do with the sun at your location.

How do I calculate the last third of the night?

Take the time from Maghrib to the next Fajr, divide it by three, and add two of those parts to Maghrib. If Maghrib is 8:00 pm and Fajr is 5:00 am, the night is nine hours, each third is three hours, and the last third begins at 2:00 am.

Does Isha have to be prayed before Islamic midnight?

Many scholars hold that the preferred time for Isha ends at Islamic midnight, with the prayer remaining valid until Fajr. Positions differ on whether delaying past midnight without excuse is disliked or sinful, so this is a question to put to a scholar rather than to a calculator.

Why does the last third move so much through the year?

Because it is anchored to sunset and dawn, both of which move. Outside the tropics the night can be six hours in summer and sixteen in winter, so a third of it varies enormously. A fixed alarm time will drift out of the window within weeks.

Does the calculation method affect these times?

Yes, through Fajr. Both are derived from the span between Maghrib and Fajr, and Fajr depends on your method's angle. A method with a 15° Fajr angle produces a shorter night than one using 18°, which moves both Islamic midnight and the start of the last third later.

Islamic midnight and the last third of the night, explained

Last updated 16 September 2026

Islamic midnight is the midpoint between Maghrib and the following Fajr, not 12:00 on the clock. The last third of the night, the preferred window for tahajjud, begins two-thirds of the way through that same span. Both drift by an hour or more across the year because they are anchored to sunset and dawn, which move.

The night is the unit, not the clock

Clock midnight is an accident of administration. It marks the middle of a timezone's day, adjusted twice a year for daylight saving, and in a wide timezone it can be more than an hour away from the sun's actual position where you are standing.

The Islamic night has a different definition entirely: it is the span from Maghrib to the following Fajr. Everything derived from it is a proportion of that span.

Time	Derivation
The night	Maghrib → next Fajr
Islamic midnight	Maghrib + half the night
Last third begins	Maghrib + two thirds of the night

A worked example makes the arithmetic concrete. If Maghrib is 8:12 pm and the next Fajr is 4:42 am, the night is eight hours and thirty minutes. Half is four hours fifteen, putting Islamic midnight at 12:27 am. Two thirds is five hours forty, putting the last third at 1:52 am.

Why it drifts, and why a fixed alarm fails

Because both ends move with the sun, the derived times move too — and outside the tropics they move a great deal.

In northern Europe the night runs to sixteen hours in midwinter and shrinks to six in midsummer. A third of it is therefore five hours in December and two in June, and the start of the last third can swing across several hours of clock time over the year.

This is why people who set a recurring 3:00 am alarm for tahajjud find it slowly stops landing in the window. It was correct on the day it was set and drifts from there — the same failure mode as a fixed 12:30 pm Dhuhr reminder, just less visible because it happens while you are asleep.

What each one is used for

Islamic midnight

It is the boundary many scholars give for the preferred time of Isha: the prayer is best offered before it, and remains valid after it until Fajr. Positions differ on how much weight to put on delaying past it, which is a matter for a scholar rather than a calculation.

Its practical value for planning is the same either way. If you know Isha's preferred window closes at 12:27 am rather than at some vague point “late”, you can decide at 11pm whether to pray now or later on the basis of something real.

The last third

This is the window associated with tahajjud, and the reason people want it as a time rather than a concept is entirely practical: it tells you when to set the alarm, and how much sleep that leaves.

Someone waking for tahajjud is making a nightly trade against the alarm they have already set for work, which is exactly the kind of thing a calendar is better at tracking than memory.

Where these numbers come from

Both are computed from Maghrib and the following Fajr, so anything that changes Fajr changes them. Your calculation method sets the Fajr angle; if you are at high latitude, the estimation rule does, and the effect there can be an hour or more.

City pages show Islamic midnight and the last third alongside the five prayers, recalculated daily, and signed-in users can have both placed on their calendar so the alarm follows the night rather than the clock.

Frequently asked questions

Is Islamic midnight the same as 12:00 am?: No, and it usually is not close. Islamic midnight is the midpoint between Maghrib and the next day's Fajr. In London in June that falls around 12:40 am; in December, closer to 11:50 pm. Clock midnight is a civil convention tied to timezones and daylight saving, neither of which has anything to do with the sun at your location.
How do I calculate the last third of the night?: Take the time from Maghrib to the next Fajr, divide it by three, and add two of those parts to Maghrib. If Maghrib is 8:00 pm and Fajr is 5:00 am, the night is nine hours, each third is three hours, and the last third begins at 2:00 am.
Does Isha have to be prayed before Islamic midnight?: Many scholars hold that the preferred time for Isha ends at Islamic midnight, with the prayer remaining valid until Fajr. Positions differ on whether delaying past midnight without excuse is disliked or sinful, so this is a question to put to a scholar rather than to a calculator.
Why does the last third move so much through the year?: Because it is anchored to sunset and dawn, both of which move. Outside the tropics the night can be six hours in summer and sixteen in winter, so a third of it varies enormously. A fixed alarm time will drift out of the window within weeks.
Does the calculation method affect these times?: Yes, through Fajr. Both are derived from the span between Maghrib and Fajr, and Fajr depends on your method's angle. A method with a 15° Fajr angle produces a shorter night than one using 18°, which moves both Islamic midnight and the start of the last third later.